Fuller regarded the principle of complementarity as a scientific generalization, as he explains in Intuition, (p.177):

"A generalization in science refers to a principle discovered by experiment to be operative in every special case. If we find any exception, we no longer have a scientific generalization."

The notion of complementarity is often cited in Synergetics, but it is not defined and is more problematical than might first appear. It is doubtful that it should even be called a principle.

Bynum, Browne, Porter have this to say about complementarity:

"A somewhat ill-defined quasi-logical relation supposed to obtain between apparently incompatible aspects of a situation whose complete description must incorporate both aspects... Attempts by Bohr, Pascual Jordan and others to extend the term's application beyond quantum physics (for example to biology and psychology) have not won general acceptance. Albert Einstein complained that he [Bohr?] was unable to give a precise formulation of complementarity, and subsequent attempts to analyse precisely the notion have not clearly answered his complaint."

Although many reasons might be suggested as to why this term has not met with general acceptance beyond its initial domain, we can see that there may be real difficulties with its applicability.

Closely related to complementarity is Heisenberg's uncertainty/indeterminacy principle. These do not seem to be equivalent, although, for instance, the Fontana Dictionary of Modern Thought provides a definition of the complementarity principle which suggests that they are:

"A principle in quantum mechanics... by which an experiment on one aspect of a system is supposed to destroy the possibility of learning about a 'complementary' aspect of the same system."

But the uncertainty/indeterminacy principle is much clearer than the notion of complementarity. The crucial point of the principle is that the experimental act of measuring one of the given pair of quantities destroys the possibility of measuring the other. This is of course a very remarkable state of affairs, which is why the principle is so significant to the foundations of quantum physics.

Now, in what way is this principle an expression of a notion which also expresses the banal difference between left and right, vertex and volume, inside and outside? The principle covers the case of the wave-particle duality, in the sense that observing light as waves precludes observing it as particles, but this type of complementarity is clearly not the same as that which might obtain, say, between left and right, or between inside and outside.

Imagine Heisenberg explaining his theory about the wave-particle duality to an audience, and some guy at the back says at the end: "I see, yes: wave-particle, cup-saucer, collar-tie".

Hence we must be very suspicious of attempts to lump together arbitrary pairings of items under the rubric of some supposed complementarity principle. If there is such a principle, it stands in need of clear definition and some justification. The least we can say here is that the way that left complements right is not the way that waves complement particles.

People of a postmodernist bent are prone to mention the uncertainty principle by way of claiming that our knowledge of the world is unfounded or non-objective. As far as I can determine from reference works, the uncertainty principle is relevant to micro-systems, i.e. particle physics, and not to macro-systems.

"Heisenberg declared that when measuring large-scale objects, the effects generated in those objects by the processes of measuring them can be neglected, since the magnitudes of the disturbances thus produced are relatively small."
(Nagel, 1961, p.295)

Arguing against the cultural constructivist doctrine of science, Gross and Levitt (1998, p.52) make the point that,

"[the uncertainty principle is] "not some brooding metaphysical dictum about the Knower versus the Known... It has been verified as fully and irrefutably as is possible for an empirical proposition. In other words, viewed as a law of physics, the uncertainty principle is a very certain item indeed. It is an objective truth about the world."



Paul Taylor 2001